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Speed signs
There are a variety of different speed signs used in NSW to show speed restrictions. These signs are usually found on poles on linesides, attached to stanchions or between tracks fastened to the sleepers if there is no space. Normal speed signs The most common types of speed sign show the safe speed limit for each type of train for a section of line so that it does not derail due to curves etc. As with all speed signs, train operators must reduce to the speed shown before reaching the sign (for a speed reduction) or wait until the entire train has passed the sign before accelerating (for a speed increase). All speeds are shown in km/h (kilometres per hour). Normal speed signs consist of a metal sign with the speed limit printed onto it. They are rectangular in shape, sometimes with cutouts on one side to form an arrow. The direction of the arrow, if any, does not have any meaning. The colour of the sign indicates which classes of train it applies to. (Note: multiple unit = no dedicated power car with no passenger seating, 4th gen train = Any train newer than an M set) Not all colours may be present at one location, so trains should follow the highest limit applicable to that class of train, except where it exceeds their maximum operating speed. Turnout speed signs These speed signs are exactly the same as arrowed speed signs described above, except they have an X printed to the left of the speed. These speed limits must be followed if the train is going through a turnout (ie. a set of points/switches). After the entire train is clear of the turnout, the previous speed can be resumed. Not all turnouts may have marked speed limits. If it is not marked, then it is assumed that the limit is 25km/h. Note that the speed limit does not have to be observed if the train is not taking the diverging path (ie. going straight ahead). There is no rectangular version of this speed sign. Advisory speed signs These are circular speed signs, which show speed limits imposed by other factors. Two signals may be very close together, leaving insufficient braking distance at track speed between the two signals. Red numbers on a yellow sign shows the speed that must be followed in order to be able to stop at the second signal. If the first signal shows a proceed indication, then normal speed may be resumed. These signs do not have to be followed by electric or diesel regional trains, as they can stop much faster than a freight train. Intermediate train stops may be used before some signals to slow the train down before a red signal is reached. White text on a black advisory sign is used to show the speed that must be achieved for the train stop to lower when the next signal is at stop. Temporary speed signs These signs are used to indicate TSRs (temporary speed restrictions) to follow due to a minor track defect, which will be resolved during the next trackwork shutdown. They are metal thin vertical signs mounted lineside. They may show three different words, along with a flashing light: Small metal plates with speeds printed on them can be affixed below and above these signs, showing speed limit. If placed below the sign, they show the next speed restriction (>50m ahead). If placed above the sign, they show the current speed restriction (<50m ahead). These plates can be either yellow (applies to all trains) or white (passenger trains only). Plates can be added above and below a CAUTION sign to have multiple restrictions within one contiguous section. Other signs can also be added above or below these speed plates to show what time these restrictions apply, or an arrow/track name showing which track is affected. Another white sign can be added below to show the distance between WARNING and CAUTION, which varies based on the braking distance required, using the words "xxx (metres) TO CAUTION" Category:Railway equipment